This invention relates to vehicle suspensions and to railcar and rubber tired vehicles equipped therewith. The invention is illustrated and described herein with reference to specific railcar and rubber tired vehicle suspensions; however, the invention is not limited to the specific suspensions illustrated and described herein and may be utilized in other vehicle suspension applications and environments.
The rubber tired vehicle suspension disclosed in the U.S. Pat. No. 3,984,125 and the railcar suspensions disclosed in U.S. Pat. Nos. 3,961,582 and 3,961,584 include multiple generally circular cross-section rod springs as the main load bearing and frictional damper spring elements.
A primary object of this invention is to provide a vehicle suspension which includes an improved rod spring and frictional damper.
Another object of this invention is to provide a vehicle suspension which, for given load and frequency conditions, is lighter in weight than suspensions which utilize circular cross-section rod springs or conventional elastomeric compression springs.
A further object of this invention is to provide a vehicle suspension of the type described which includes a single rod spring as both the main load bearing and frictional damper spring element.
A still further object of this invention is to provide a vehicle suspension of the type described which includes a rod spring affording a lower suspension frequency for a given amount of elastomeric material than heretofore possible using circular cross-section rod springs, or conventional elastomeric compression springs.
Another object of this invention is to provide a vehicle suspension of the type described which affords a substantially constant frequency over a predetermined load range.
Still another object of this invention is to provide a vehicle suspension of the type described which affords self-steering when negotiating a curve.
An object of this invention which is related to that just stated is to provide a self-steering railcar truck of double axle, single axle, or articulated single axle construction.
A still further object of this invention is to provide a vehicular suspension of the type described which includes a frictional damper, preferably of the variable rate type, having self-adjustment for wear so as to maintain essentially the same percentage efficiency throughout the service life of the wear material.